Hi Gina 24r,
Since the project is due in 3 days, you barely have time to grow bacteria and write up the project, but here are some options for completing your science fair project.
It sounds like you used gelatin for the plates, and of course, the weather has been too warm and the gelatin melted. You could recover the Petri dishes you have, soak them in 70% isopropanol for an hour and dry them with a hair dryer. This would give you reasonably sterile Petri dishes again. Next, you would need to purchase agar from a health food store or Asian grocery store and prepare your growth medium again. Agar melts when it is boiled, and solidifies at about 50 degrees Centigrade, so you would boil it and then let it cool before repouring the plates. The science buddies website has lots of information on preparing agar and other microbiological techniques:
https://www.sciencebuddies.org/science- ... ndex.shtml
If you are able to prepare the plates today and inoculate them, you would expect to see growth maybe by Tuesday morning.
Another option is to go ahead and write up this project and present your results as they happened. It sounds like you had a good experiment, but did not have any results because the growth medium melted. You can still have your son write up the project including the title, purpose, hypothesis, materials, procedure, results, conclusion and bibliography sections; you should refer to the teacher’s handout and follow the specific instructions given for this assignment. The science buddies website has some excellent suggestions for writing up the board:
https://www.sciencebuddies.org/science- ... oard.shtml
Here is some information on gelatin, including the melting point (35 degrees Centigrade).
http://www.gelatin.co.za/gltn1.html
Of course, you won’t have any quantitative results to report, but you can take a photograph or make a drawing of the melted gelatin plates. You can compensate for the lack of results by including an extensive discussion section explaining the science behind why the project did not work as expected, and by stating what you would do differently next time (use agar, start earlier, etc.) The teacher and the science fair judges are primarily interested in seeing if your son understands the science behind his project and can apply the scientific method in designing an experiment, so the project will receive full credit for most of the sections.
I hope this helps. Let me know if you have any other questions.
Donna Hardy